Huawei Technologies Co., Limited

Zhejiang University

Jianwei Zhou

Hejia Luo

Chenlei Xu

Xiaolu Wang

Jian Wang

Rong Li

Ying Chen

Yunfei Qiao

Yu Wang

Donghong Liu

Xingqian Ye

Huan Cheng

Tian Ding

Enbo Xu

Zhenjun Jiang

Yinggang Du

Bin Wang

Hao Wang

A bandwidth part switching method, is applicable to a non-terrestrial network (NTN) to implement BWP switching based on multi-color frequency-division multiplexing. In the method, a terminal device may report, in a second BWP to a network device, an index of a first SSB whose signal quality is greater than or equal to a first threshold in one or more SSBs in a first BWP, and switch from the second BWP to a third BWP. The one or more SSBs correspond to at least one BWP other than the first BWP, and the third BWP is in the at least one BWP and corresponds to the first SSB. After receiving the index of the first SSB in the second BWP, the network device determines the third BWP, and performs service data transmission with the terminal device in the third BWP.

Bandwidth part switching method, apparatus, and system

A communication method and apparatus are provided, and relate to the field of wireless communication technologies, to resolve a problem in a conventional technology that communication quality during communication between a satellite and a communication apparatus cannot be ensured, and to ensure security of high-accuracy location information of the satellite. In the method, the communication apparatus may perform random access to the satellite based on first location information. The communication apparatus may perform uplink communication with the satellite based on obtained second location information. Accuracy of a location obtained based on the second location information is higher than accuracy of a location obtained based on the first location information. Based on this solution, required accuracy of location information of the satellite is different.

Communication method and apparatus

An uplink signal sending and receiving method includes that a first communication apparatus obtains a first timing advance (TA) change rate, and sends an uplink signal in a plurality of first time periods. There is a first time interval between the plurality of first time periods to compensate for a time synchronization drift. A length of the first time interval and a location of the first time interval between the plurality of first time periods are determined based on the first TA change rate, and the first TA change rate is a TA change rate in a communication process of the first communication apparatus.

Uplink signal sending and receiving method, and apparatus

A terminal determines a first frequency for accessing the network device Then, the terminal determines at least one second frequency based on the first frequency, where any second frequency is different from the first frequency, and at least two second frequencies are also different. The terminal selects at least two different second frequencies from the first frequency and the at least one second frequency. The terminal separately receives, in a time unit in a period by using the at least two different frequencies, an SSB from the network device. The terminal accesses the network device based on received one or more different SSBs.

This application discloses a random access preamble configuration method applicable to a satellite network and a communication apparatus. In the method, a random access preamble location offset and duration of a PRACH occasion can be flexibly configured based on features of a satellite system. The method includes: A receiving apparatus receives first indication information, where the first indication information includes indication information used to identify the random access preamble location offset at the physical random access channel PRACH occasion. The receiving apparatus transmits a random preamble based on the first indication information, where the random preamble includes a sequence part and a guard time. Because a communication distance is relatively long and a transmission delay difference between users is relatively large in a satellite communication system, time domain resources occupied by the PRACH occasion can be minimized by using this method.

Random access preamble configuration method applicable to satellite network, and apparatus

This application discloses example signal sending methods and apparatuses, and example signal processing methods and apparatuses. One example method includes generating, by a terminal device, a channel sounding reference signal (SRS). The terminal device can then send the SRS to a target base station, where the target base station detects, by using the SRS, that a change range of an uplink timing location of the terminal device is not less than a length of one SRS symbol.

Signal sending and processing method and apparatus

The present disclosure relates to access methods and apparatuses. In one example method, a terminal device determines, based on whether a first frequency offset parameter is in a frequency offset parameter range, whether to access a first cell. If the first frequency offset parameter is in the frequency offset parameter range, a current location of the terminal device is not at an edge of the cell. Otherwise, the current location of the terminal device may be at the edge of the cell.

Access method and apparatus

This disclosure provides data processing methods. One example including a network device obtains target information that includes a transmission delay difference corresponding to a target beam or a target cell; determines a first preamble format based on the transmission delay difference, and then determines first configuration information used to indicate the first preamble format and a first set of random access occasions included in a random access period, where an interval between random access times included in the first set of random access occasions is greater than or equal to a preamble length corresponding to the first preamble format; and generates a corresponding first configuration index based on the first configuration information. The preamble formats required for different beams or cells can be determined based on transmission delay differences corresponding to the different beams or cells, and then configuration information of a random access occasion is further determined.

Data processing method and apparatus, and storage medium

The present disclosure relates to random access preamble transmission methods, apparatuses, and storage mediums. In one example method, a terminal device determines, based on a target sub-coverage area to which the terminal device belongs in a preset coverage area of a network device, target random access preamble format information corresponding to the target sub-coverage area. Then, the terminal device sends, to the network device on a target time-frequency resource indicated by target random access preamble time-frequency resource information corresponding to the target random access preamble format information, a random access preamble corresponding to the target random access preamble format information.

Random access preamble transmission method, apparatus, and storage medium

The present disclosure relates to network switching methods and apparatuses. In one example method, a beam that currently provides a service for a terminal device is a first beam. The first beam is generated by a first network device. The first network device obtains user information of the terminal device, and obtains switching information based on the user information. After the first network device sends the switching information to the terminal device, the terminal device can perform beam switching based on the switching information.

Network switching method and apparatus

This application provides a satellite communication method and apparatus. A terminal obtains a level-1 broadcast signal from a satellite, where a beam status corresponding to the level-1 broadcast signal is an energy saving state, and the level-1 broadcast signal includes synchronization information. The terminal obtains a level-2 broadcast signal from the satellite, where a beam status corresponding to the level-2 broadcast signal is a broadband communication state. The terminal communicates with the satellite based on the level-2 broadcast signal.

Satellite communication method and apparatus

A terminal apparatus is provided. The terminal apparatus obtains synchronization signal and physical broadcast channel (PBCH) blocks (SSBs) in a plurality of beams; then determines a target beam in the plurality of beams based on an association relationship between an SSB index and a first random access preamble, where the first random access preamble is determined based on a cyclic shift and/or an order of symbols; and finally sends the random access preamble by using the target beam to initiate a random access request. A communication device receives the first random access preamble in the random access request sent by the terminal apparatus, and then, determines, based on the association relationship, the target beam accessed by the terminal apparatus. The first random access preamble is determined based on the cyclic shift and/or the order of symbols.

Beam establishment method and apparatus

Example communication methods and apparatus are described. In one example method, a terminal receives a first information by using a serving beam, where the first information indicates a delay compensation parameter corresponding to a target beam. The target beam and the serving beam are different beams. The terminal determines, based on a full timing advance and the delay compensation parameter corresponding to the target beam, a differential timing advance corresponding to the target beam.

This application provides example satellite communication methods and example apparatuses. One example method includes receiving, by a terminal device, first information sent by a satellite, where the first information indicates a first timing change rate range. The terminal device can then measure a downlink timing change rate to obtain a first downlink timing change rate. The terminal device can then determine a first uplink timing change rate based on the first downlink timing change rate and the first timing change rate range. The terminal device can then perform uplink communication with the satellite based on the first uplink timing change rate.

Example signal transmission methods based on satellite communication and apparatus are described. One example method includes: obtaining, by a communication device, carrier attribute information corresponding to a target carrier used to transmit an orthogonal frequency division multiplexing (OFDM) symbol. The carrier attribute information of the target carrier includes subcarrier spacing. The communications device determines a cyclic prefix (CP) length of the OFDM symbol based on the carrier attribute information of the target carrier and a preset correspondence between carrier attribute information and the OFDM symbol. The CP is used to carry first data. The first data is data in the OFDM symbol.

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Hangzhou, China

Jianwei Zhou